It is known to form a tube by taking an elongate sheet of material having a pair of spaced, parallel lateral edges and bending the material about a longitudinal axis so that the lateral edges abut or overlap so as to form a tube. Thereafter, the abutting or overlapping lateral edges are fixed together, usually by welding, riveting or the like.
The present invention relates to a novel method of fixing together overlapping lateral edges during formation of a tube, and to a tube thus formed.